Robert Platshorn served thirty years in prison for smuggling pot into Florida. That's more than any other person has served for a marijuana offense in the United States. He'll turn 70 years old in November.

The guy's closer to Jack LaLanne than Pablo Escobar. But now-- despite claiming to have fulfilled his parole-- he's facing a return to prison for a failed piss test.

Platshorn, who was originally sentenced to prison in 1980, began his parole in September 2008. It was essentially a lifetime parole sentence, with the possibility for early termination.

Platshorn's parole officer, Anthony Gagliardi, had allowed him to travel to marijuana-related conferences and speaking engagements. And Platshorn says, he had okayed his use of a cannabis oil to treat skin cancer. In May 2011, Platshorn received what he claims in a recent lawsuit is a release from federal parole supervision:

The trouble began about a year ago, Platshorn says, when Gagliardi became ill. Six weeks ago, the former smuggler's new parole officer, Scott T. Kirsche-- apparently peeved that he had attended the High Times Cannabis Cup-- showed up at Platshorn's home and demanded a urine sample.

Because of the cannabis oil, Platshorn says, the sample tested dirty. Depending on the outcome of a parole board review, Platshorn could be headed back to prison. In the meantime, Platshorn says, he has been urine tested six times since-- with the results returning clean each time-- and will now face frequent testing. He's also been banned from travelling.

Platshorn, who earns $600 a month from social security, says that money he makes at engagements amounts to eighty percent of his income. He is a figurehead in the national medical marijuana movement.

Platshorn has also been barred from associating with Irv Rosenfeld, one of the few Americans to get medical pot from the federal government. Rosenfeld, who has joined Platshorn on his Silver Tour to educate seniors about medical marijuana, is not a criminal.

On June 15, Platshorn filed suit against the federal government and the United States Parole Commission. He claims that he is being targeted for his activism. "Kirsche... has conspired to and has effectively ceased Robert Platshorn's political activities for the legalization of medical cannabis nationwide," the suit reads.

We left a message for Kirsche this morning, and will update this post if we hear back.

Hounding a septuagenarian, who has by any metric served his time, to pee in cups and stop travelling the country is a pretty wonderful waste of federal resources. But to Platshorn and his wife, it's just plain scary. "My wife is frightened to leave the house because she's afraid that I won't be there when I come back," he says, before adding that he remains optimistic that the federal government will ease up: "I survived thirty years in prison by keeping a positive attitude, hoping for a pardon or that somebody would come to my rescue with the realization that nobody's supposed to spend thirty years in prison for a weed."

"That didn't happen," he adds, "but it sure as hell helped me get through through it all."